You have to add the init script which is starting the service smb from /etc/init.d to your /etc/rcX.d. Where X is your runlevel There is a program chkconfig which you first may have to install from the debian repository allowing you to do this quite easy (I am just not sure whether it is in the default installation):

apt-get install chkconfig

Now you can add the service smb to start with your system by typing as root: